HHT

HHT may refer to:
 * Human-to-human transmission of infectious disease
 * Headquarters and Headquarters Troop, in the U.S. Army
 * Heinrich Hertz Submillimeter Telescope
 * Heinrich-Hertz-Turm, in Hamburg, Germany
 * Hereditary hemorrhagic telangiectasia, or Rendu-Osler-Weber disease
 * Hilbert–Huang transform
 * Hiphop Tamizha, an Indian musical duo
 * Historic House Trust of New York City
 * Historic Houses Trust, New South Wales
 * Omega-hydroxypalmitate O-feruloyl transferase, an enzyme
 * Howard Thompson (film critic), who wrote under the pen name HHT